Cydia

iOS developer Elias Limneos released a new jailbreak tweak on Saturday dubbed VoiceChanger that will let you change the sound of your voice during a live phone call on your iPhone.

The developer notes that this is the first jailbreak tweak of its kind, as it can change the sound of your voice in real time as you’re speaking to the people on the other line. This means you can effectively mask your voice, and this makes for great pranks.

After installing the tweak, there will be a new preferences pane in the Settings application where you can enable and disable the tweak on demand, as well as set the voice that you want to speak as:

The included voice effects include:

Dark Lord

Tenoro

Smurf

Rumpelstiltskin

No effect (normal voice)

The voices can be changed mid-call by just exiting the phone application during the call and changing your voice style.

At this point in time, VoiceChanger supports the iPhone 4S and iPhone 5 running iOS 5.0 or later. The tweak will not work on an iPhone 4 or older, likely due to hardware limitations.

The package is available in Cydia's BigBoss repository right now for $2.99. Well worth all the fun you'll have!